Lubricant composition promoting sustained fuel economy

ABSTRACT

A lubricant composition includes a controlled release friction modifier (CRFM), a highly paraffinic base stock, a dispersant and a detergent. The CRFM includes an ionic tetrahedral borate compound including a cation and a tetrahedral borate anion, wherein the tetrahedral borate anion comprises a boron atom having two bidentate di-oxo ligands of C18 tartrimide. The lubricant composition can also include at least one of a Group V co-base stock, an inorganic friction modifier, a viscosity modifier, and a cleanliness booster.

This nonprovisional application claims priority to U.S. ProvisionalApplication No. 62/535,509, which was filed on Jul. 21, 2017, and isherein incorporated by reference.

BACKGROUND OF THE INVENTION Field of the Disclosure

The present invention relates to a lubricant composition, in particularto a lubricant composition suitable for use in internal combustionengines, which promotes sustained improved fuel economy.

Description of the Background Art

Lubricant compositions must provide crucial lubrication to engines, butthese compositions must also provide additional benefits to the enginesin which they are used. Such additional benefits include fuel economy,oxidation stability of the composition over time, control of depositformation on internal engine surfaces and maintenance of thefilterability of the composition. In addition, lubricant compositionsmust be formulated to meet stringent government testing standards beforeit may be used as a motor oil. Because of all of these requirements,formulating a lubricant composition that meets these requirements isquite difficult.

Various additives are included in a lubricant composition to achieve theabove benefits. Improving any of these benefits while maintaining theothers is challenging because a particular additive that may improve onebenefit will often negatively affect at least one of the other requiredbenefits of a lubricant composition. In view of the chemicalinteractions both among the additives and between the additives and thebase stock used, developing a formulation for a lubricant compositionthat provides the above benefits is a difficult and complex task.

Friction modifiers, which are among the additives used in lubricantcompositions, are used to improve the composition's ability to reducefriction. Among the friction modifiers that can be used in a lubricantcomposition are borated friction modifiers. Documents disclosingconventional borated friction modifiers include U.S. Pat. No. 4,522,734Adisclosing borated long-chain (C10-20) epoxides, EP 0036708A1 disclosingborated fatty acid esters of glycerol, U.S. Pat. No. 5,759,965Adisclosing borated alkoxylated fatty amines, US 2009/0005276A1disclosing borated polyalkene succinimides, WO 2007005423A2 disclosing areaction product of C8-20 fatty acids with dialkanolamines and boricacid, CA 1336830C disclosing borated hydroxyl ether amines and U.S. Pat.No. 4,522,629A disclosing borated phosphonates. While these documentsdisclose borated friction modifiers, there still exists a need forlubricant compositions including borated friction modifiers, whichbetter facilitate improvements in the necessary benefits describedabove.

Known lubricant compositions for use as motor oils are described indocuments such as U.S. Pat. No. 9,193,934B2, U.S. Pat. No. 9,163,196B2,US 2014/0045734A1, U.S. Pat. No. 9,175,241B2, US 2012/0283158A1 and US2014/0107000A1. These documents describe compositions that have beenformulated for clarity and stability; however, they do not describecompositions that have been formulated to provide increased fuel economythat is sustained while the lubricant composition ages. Accordingly,there exists a need for improved lubricant compositions capable ofproviding increased fuel economy that is sustained over the periodduring which the composition is used, while meeting all of therequirements for the use of a lubricant composition in an engine.

A major source of energy loss within internal combustion engines is thefriction that occurs between lubricated parts that are in slidingcontact with each-other during the combustion cycle. Critical engineparts that often contribute to these losses include piston ring on linercontact, cam lobe contacts and journal bearings. Friction modifiers arecapable of changing the surface properties of the materials commonlyused in engines. Although both inorganic (metal ash-containing) andorganic (ash-free) friction modifiers exist, organic friction modifiersare preferred as they do not contribute to ash in the exhaust stream. Itis well known that friction modifiers (especially organic frictionmodifiers) are quickly destroyed in high temperatures and oxidativeenvironments such as those that are present in a combustion engine. Itis therefore advantageous to develop formulations with ControlledRelease Friction Modifiers that allow for low friction benefits to beretained hours, days, weeks and even months after the lubricant has beenadded to the engine. The use of a controlled release friction modifiercan enable a vehicle to have better aged-oil fuel economy than fresh oilfuel economy. This is important for minimizing the carbon intensity ofthe lubricant over the entire lubricant drain interval. However,controlled release friction modifiers often are accompanied bysolubility limitations of the friction modifier, poor depositperformance and poor filterability of the finished lubricant. Until now,this has prohibited the development of high-performing controlledrelease friction modified formulations.

Fuel economy, enabled by an engine oil lubricant, is a key specificationfor automotive lubricants. Traditionally, fuel economy favors lowerviscosity engine oils and the use of friction modifying additives. Fueleconomy, often measured in operating engine tests, is only one of manyperformance needs of a modern engine oil. Others include oxidationstability of the lubricant over time, deposit formation on internalengine surfaces and a variety of physical and chemical tests needed toensure the oil will be suitable in an engine. Because there are manyrequirements, the chemistry used to formulate engine oils is complex.Often a particular additive that can improve one aspect of a lubricantsperformance works against the performance enabled by other additives.Current well known fuel economy additives include various oil-solublecompounds of molybdenum as well as NOCH (nitrogen, oxygen-containingchemistries). The highest performance lubricants usually entail the useof base oils that are highly paraffinic. Such base oils would includeAPI Group IV PAO's, API Group III's such as gas-to-liquids base oils andpotentially even highly saturated Group II base oils. Such oils arehighly non-polar, and as a result have a limited solubility for polaradditives. Most of the fuel economy additives are highly polar and assuch are challenged to remain soluble in the lube oil. With limitedsolubility and availability of the additives, improvements in fueleconomy are similarly limited. In addition, many of the additivesdegrade or are used up in service, with the result that fuel economy ismore difficult to maintain for extended times. A key indicator of thiswould be tests such as the API/ILSAC Seq. VID or VIE, which measures thefuel economy of both fresh and aged oils against a reference.

SUMMARY OF THE INVENTION

In view of the foregoing and other exemplary problems, drawbacks anddisadvantages of the conventional methods and compositions, an exemplaryfeature of the present invention is to improve engine fuel economy byproviding a controlled release friction modified lubricant formulationwith sustained fuel economy.

Exemplary embodiments of the invention are directed to a lubricantcomposition that includes a controlled release friction modifier (CRFM),a highly paraffinic base stock selected from at least one Group III basestock, at least one Group IV polyalphaolefin (PAO) base stock, orcombinations thereof, a dispersant, and a detergent. In certainembodiments, the CRFM comprises an ionic tetrahedral borate compoundincluding a cation and a tetrahedral borate anion, wherein thetetrahedral borate anion comprises a boron atom having two bidentatedi-oxo ligands of C₁₈ tartrimide.

In certain embodiments, the lubricant composition also includes at leastone of a Group V co-base stock, an inorganic friction modifier, aviscosity modifier, and a cleanliness booster.

Exemplary lubricant compositions of the present invention can be used asengine lubricants that promote fuel economy in internal combustionengines. This fuel economy is not only sustained, but actually increasesover the time the composition is utilized.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given herein below and the accompanying drawingswhich are given by way of illustration only, and thus, do not limit thepresent invention, and wherein:

FIG. 1 illustrates comparative aging profile results from engine teststand testing of a composition consistent with embodiments of thepresent invention.

FIG. 2 illustrates comparative fuel economy change calculated fromresults of full chassis dynamometer testing of a composition consistentwith embodiments of the present invention.

DETAILED DESCRIPTION

Aspects of the invention are disclosed in the following description andrelated drawings directed to specific embodiments of the invention.Alternate embodiments may be devised without departing from the scope ofthe invention. Additionally, well-known elements of the invention willnot be described in detail or will be omitted so as not to obscure therelevant details of the invention.

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration.” Any embodiment described herein as“exemplary” is not necessarily to be construed as preferred oradvantageous over other embodiments. Likewise, the term “embodiments ofthe invention” does not require that all embodiments of the inventioninclude the discussed feature, advantage or mode of operation.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of embodiments ofthe invention. As used herein, the singular forms “a”, “an” and “the”are intended to include the plural forms as well, unless the contextclearly indicates otherwise. It will be further understood that theterms “comprises”, “comprising,”, “includes” and/or “including”, whenused herein, specify the presence of stated features, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

The present invention is directed to a lubricant composition suitablefor use as an engine oil, the usage of which results in improved fueleconomy throughout the time that the composition is used in an engine.In some embodiments, the lubricant composition comprises a controlledrelease friction modifier (CRFM). Additionally, in some embodiments, thelubricant composition further comprises a highly paraffinic base stockselected from at least one an American Petroleum Institute (API) GroupIII base stock, at least one API Group IV polyalphaolefin (PAO) basestock, or combinations thereof, a dispersant and a detergent. In someembodiments, the lubricant composition further comprises at least oneof, a Group V co-base stock, an inorganic friction modifier, a viscositymodifier, a cleanliness booster, as well as other lubricant compositionadditives.

Controlled Release Friction Modifier (CRFM)

In accordance with certain exemplary aspects of the present invention,the lubricating composition includes a CRFM. The CRFM is adispersant-stabilized, borated CRFM comprising an ionic tetrahedralborate compound including a tetrahedral borate anion having a boron atomwith two bidentate di-oxo ligands both being a linear C18-tartrimide, afirst dispersant comprising a conventional ammonium substitutedpolyisobutenyl succinimide compound having a polyisobutenyl numberaverage molecular weight of 750 to 2,500, a second dispersant comprisingan ammonium substituted polyisobutenyl succinimide compound having anN:CO ratio of 1.8 and a polyisobutylenyl number average molecular weightof 750 to 2,500, wherein one or more of the first dispersant and thesecond dispersant are in cationic form. As used herein, the term“conventional ammonium substituted polyisobutenyl succinimide,” refersto an ammonium substituted polyisobutenyl succinimide made by thechorine-assisted process. Such a process is well known in the art. Onesuch process includes grafting maleic anhydride to polyisobutenyl in thepresence of chorine followed by reaction with a poly(amine) to form theimide.

In accordance with another aspect of the exemplary embodiment, the CRFMincludes a reaction product of a trivalent boron compound, such as boricacid, with a tartaric acid and a linear C18 amine under conditionssuitable to form an ionic tetrahedral borate compound. The ionictetrahedral borate compound is combined with a first dispersantcomprising a conventional ammonium substituted polyisobutenylsuccinimide compound having a polyisobutenyl number average molecularweight of 750 to 2,500, a second dispersant comprising an ammoniumsubstituted polyisobutenyl succinimide compound having an N:CO ratio of1.8 and a polyisobutylenyl number average molecular weight of 750 to2,500, wherein one or more of the first dispersant and the seconddispersant are converted to a cationic form.

The above described ionic tetrahedral borate compound can serve as afriction modifier, in a lubricating composition.

In one embodiment, the structure of the tetrahedral borate ion of thetetrahedral borate compound may be represented by the structure shown inFormula I:

where R3 and R4 form a 5 membered nitrogen-containing heterocyclic ringsubstituted with a linear C18 group.

The cations in Formula I include one or more of a first ammonium cationincluding a conventional polyisobutylene succinimide with number averagemolecular weight of the polyisobutylene substituent of at least 750, andcan be up to 2500, and a second ammonium cation is including apolyisobutylene succinimide with number average molecular weight of thepolyisobutylene substituent of at least 750, and can be up to 2,500,having an N:CO ratio of 1.8. Such succinimides can be formed, forexample, from high vinylidene polyisobutylene and maleic anhydride.

Total base number (TBN) is the quantity of acid, expressed in terms ofthe equivalent number of milligrams of potassium hydroxide (meq KOH),that is required to neutralize all basic constituents present in 1 gramof a sample of the lubricating oil. The TBN may be determined accordingto ASTM Standard D2896-11, “Standard Test Method for Base Number ofPetroleum Products by Potentiometric Perchloric Acid Titration” (2011),ASTM International, West Conshohocken, Pa., 2003 DOI: 10.1520/D2896-11(hereinafter, “D2896”).

Specific examples of such amine and ammonium compounds includepolyisobutylene derived succinimide dispersants wherein thepolyisobutylene may be 1000 Mn and the succinimide amine is apolyethylenepolyamine (Mn 1700 g/mol).

A useful molar ratio of the tartaric acid, the trivalent boron compound,and counter ion charge used in forming the combination and/or reactionproduct is 2:1:1.

In an embodiment the linear C18 tartrimide compound is derived fromtartaric acid. The tartaric acid used for preparing the tartrates of theinvention can be commercially available, and it is likely to exist inone or more isomeric forms such as d-tartaric acid, I-tartaric acid,d,l-tartaric acid, or mesotartaric acid, often depending on the source(natural) or method of synthesis (from maleic acid). For example aracemic mixture of d-tartaric acid and l-tartaric acid is obtained froma catalyzed oxidation of maleic acid with hydrogen peroxide (withtungstic acid catalyst). These derivatives can also be prepared fromfunctional equivalents to the diacid readily apparent to those skilledin the art, such as esters, acid chlorides, or anhydrides. The suitableamines will have the formula RNH2 wherein R represents a hydrocarbylgroup, typically of 6 to 26. Exemplary primary amines includen-hexylamine, n-octylamine (caprylylamine), n-decylamine, n-dodecylamine(laurylamine), n-tetradecylamine (myristylamine), n-pentadecylamine,n-hexadecylamine (palmitylamine), n-octadecylamine (stearylamine), andoleylamine.

Suitable trivalent boron compounds include borate esters of the generalform B(OR)3 where each R is 2-propylheptyl. In an embodiment, thecounter ion is a basic component, such as a dispersant. The source ofthe counter ion may be an aminic dispersant. For solubilization inmineral oil, particular examples include polyisobutenyl succinimide andpolyamine dispersants with a N:CO ratio of 1.8 and with a TBN of atleast 50.

In an embodiment, the ionic borate compound is the reaction product of atartrimide, a borate ester, and a basic component, such as twodispersants, to form a “boro-tartrimide” friction modifier. The ionicboron compound described herein is used to improve friction.

A problem with conventional friction modifiers, as noted above, is thatthe friction modifier is not sufficiently soluble, which leads to aninsufficient amount of friction modifier being available duringconsumption of the lubricating oil and sludge (i.e., deposits) may form.The CRFM in accordance with certain exemplary embodiments of the presentinvention maintains sufficient friction modifier at the surface toprovide lower friction lubricating oils while improving overall fueleconomy. That is, the CRFM described herein raises the amount offriction modifier by using a tetra-valent boron chemistry to complex thefriction modifier. This results in a much larger amount of frictionmodifier in the lubricating oil with resulting improvements to fueleconomy. Also, it is known that ash can damage the particulate filter ofan engine. High ash compositions (i.e., compositions with high amountsof detergent) are not desirable. The present CRFM is preferably a lowash CRFM.

In accordance with certain exemplary embodiments of the presentinvention, the CRFM is an ashless, dispersant-stabilized, boratedfriction modifier. Additionally, the lubricating oil composition mayinclude an amount of CRFM in a range of 2 wt % to 8 wt %, and morepreferably in a range of 3 wt % to 5 wt %, of the total lubricating oilcomposition. In certain specific preferred embodiments, the CRM isprovided in an amount of 3.96 wt %.

Base Stocks

In certain exemplary embodiments of the present invention, thelubricating composition includes API Group III base oils and/or APIGroup IV polyalphaolefin (PAO) base oils as base stock. In certainexemplary embodiments, the lubricant composition also includes API GroupV base oil as a co-base stock.

A wide range of lubricating base oils is known in the art. Lubricatingbase oils are both natural oils and synthetic oils. Natural andsynthetic oils (or mixtures thereof) can be used unrefined, refined, orrerefined (the latter is also known as reclaimed or reprocessed oil).Unrefined oils are those obtained directly from a natural or syntheticsource and used without added purification. These include shale oilobtained directly from retorting operations, petroleum oil obtaineddirectly from primary distillation, and ester oil obtained directly froman esterification process. Refined oils are similar to the oilsdiscussed for unrefined oils except refined oils are subjected to one ormore purification steps to improve at least one lubricating oilproperty. One skilled in the art is familiar with many purificationprocesses. These processes include solvent extraction, secondarydistillation, acid extraction, base extraction, filtration, andpercolation. Rerefined oils are obtained by processes analogous torefined oils but using an oil that has been previously used as feedstock.

Diverse groups of lubricant base stocks are known in the art. Groups I,II, III, IV and V are broad categories of base oil stocks developed anddefined by the American Petroleum Institute (API Publication 1509) tocreate guidelines for lubricant base oils. Group I base stocks have aviscosity index of between about 80 to 120 and contain greater thanabout 0.03% sulfur and less than about 90% saturates. Group II basestocks have a viscosity index of between about 80 to 120, and containless than or equal to about 0.03% sulfur and greater than or equal toabout 90% saturates. Group III stocks have a viscosity index greaterthan or equal to 120 and contain less than or equal to about 0.03%sulfur and greater than about 90% saturates. Group IV includespolyalphaolefins (PAO). Group V base stock includes base stocks notincluded in Groups I-IV. Table 1 below summarizes properties of each ofthese five groups.

TABLE 1 Base Oil Properties Saturates Sulfur Viscosity Index Group I <90 and/or  >0.03% and ≥80 and <120 Group II ≥90 and ≤0.03% and ≥80 and<120 Group III ≥90 and ≤0.03% and ≥120 Group IV polyalphaolefins (PAO)Group V All other base oil stocks not included in Groups I, II, III, orIV

Natural oils include animal oils, vegetable oils (castor oil and lardoil, for example), and mineral oils. Animal and vegetable oilspossessing favorable thermal oxidative stability can be used. Of thenatural oils, mineral oils are preferred. Mineral oils vary widely as totheir crude source; for example, as to whether they are paraffinic,naphthenic, or mixed paraffinic-naphthenic. Oils derived from coal orshale are also useful. Natural oils vary also as to the method used fortheir production and purification; for example, their distillation rangeand whether they are straight run or cracked, hydrorefined, or solventextracted.

Group II and/or Group III hydroprocessed or hydrocracked base stocks, aswell as synthetic oils such as polyalphaolefins, alkyl aromatics andsynthetic esters, i.e. Group IV and Group V oils are also well knownbase stock oils.

Synthetic oils include hydrocarbon oil such as polymerized andinterpolymerized olefins (polybutylenes, polypropylenes, propyleneisobutylene copolymers, ethylene-olefin copolymers, andethylene-alphaolefin copolymers, for example). Polyalphaolefin (PAO) oilbase stocks, the Group IV API base stocks, are a commonly used synthetichydrocarbon oil. By way of example, PAOs derived from C8, C10, C12, C14olefins or mixtures thereof may be utilized. See U.S. Pat. Nos.4,956,122; 4,827,064; and 4,827,073, which are incorporated herein byreference in their entirety. Group IV oils, that is, the PAO base stockshave viscosity indices preferably greater than 130, more preferablygreater than 135, still more preferably greater than 140.

The number average molecular weights of the PAOs, which are knownmaterials and generally available on a major commercial scale fromsuppliers such as ExxonMobil Chemical Company, Chevron Phillips ChemicalCompany, BP, and others, typically vary from about 250 to about 3,000,although PAO's may be made in viscosities up to about 150 cSt (100° C.).The PAOs are typically comprised of relatively low molecular weighthydrogenated polymers or oligomers of alphaolefins which include, butare not limited to, C2 to about C32 alphaolefins with the C8 to aboutC16 alphaolefins, such as 1-octene, 1-decene, 1-dodecene and the like,being preferred. The preferred polyalphaolefins are poly-1-octene,poly-1-decene and poly-1-dodecene and mixtures thereof and mixedolefin-derived polyolefins. However, the dimers of higher olefins in therange of C14 to C18 may be used to provide low viscosity base stocks ofacceptably low volatility. Depending on the viscosity grade and thestarting oligomer, the PAOs may be predominantly trimers and tetramersof the starting olefins, with minor amounts of the higher oligomers,having a viscosity range of 1.5 to 12 cSt. PAO fluids of particular usemay include 3.0 cSt, 3.4 cSt, and/or 3.6 cSt and combinations thereof.Mixtures of PAO fluids having a viscosity range of 1.5 to approximately150 cSt or more may be used if desired.

The PAO fluids may be conveniently made by the polymerization of analphaolefin in the presence of a polymerization catalyst such as theFriedel-Crafts catalysts including, for example, aluminum trichloride,boron trifluoride or complexes of boron trifluoride with water, alcoholssuch as ethanol, propanol or butanol, carboxylic acids or esters such asethyl acetate or ethyl propionate. For example the methods disclosed byU.S. Pat. No. 4,149,178 or 3,382,291 may be conveniently used herein.Other descriptions of PAO synthesis are found in the following U.S. Pat.Nos. 3,742,082; 3,769,363; 3,876,720; 4,239,930; 4,367,352; 4,413,156;4,434,408; 4,910,355; 4,956,122; and 5,068,487. The dimers of the C14 toC18 olefins are described in U.S. Pat. No. 4,218,330.

Other useful lubricant oil base stocks include wax isomerate base stocksand base oils, comprising hydroisomerized waxy stocks (e.g. waxy stockssuch as gas oils, slack waxes, fuels hydrocracker bottoms, etc.),hydroisomerized Fischer-Tropsch waxes, Gas-to-Liquids (GTL) base stocksand base oils, and other wax isomerate hydroisomerized base stocks andbase oils, or mixtures thereof. Fischer-Tropsch waxes, the high boilingpoint residues of Fischer-Tropsch synthesis, are highly paraffinichydrocarbons with very low sulfur content. The hydroprocessing used forthe production of such base stocks may use an amorphoushydrocracking/hydroisomerization catalyst, such as one of thespecialized lube hydrocracking (LHDC) catalysts or a crystallinehydrocracking/hydroisomerization catalyst, preferably a zeoliticcatalyst. For example, one useful catalyst is ZSM-48 as described inU.S. Pat. No. 5,075,269, the disclosure of which is incorporated hereinby reference in its entirety. Processes for makinghydrocracked/hydroisomerized distillates andhydrocracked/hydroisomerized waxes are described, for example, in U.S.Pat. Nos. 2,817,693; 4,975,177; 4,921,594 and 4,897,178 as well as inBritish Patent Nos. 1,429,494; 1,350,257; 1,440,230 and 1,390,359. Eachof the aforementioned patents is incorporated herein in their entirety.Particularly favorable processes are described in European PatentApplication Nos. 464546 and 464547, also incorporated herein byreference. Processes using Fischer-Tropsch wax feeds are described inU.S. Pat. Nos. 4,594,172 and 4,943,672, the disclosures of which areincorporated herein by reference in their entirety.

Gas-to-Liquids (GTL) base oils, Fischer-Tropsch wax derived base oils,and other wax-derived hydroisomerized (wax isomerate) base oils beadvantageously used in the instant disclosure, and may have usefulkinematic viscosities at 100° C. of about 3 cSt to about 50 cSt,preferably about 3 cSt to about 30 cSt, more preferably about 3.5 cSt toabout 25 cSt, as exemplified by GTL 4 with kinematic viscosity of about4.0 cSt at 100° C. and a viscosity index of about 141. TheseGas-to-Liquids (GTL) base oils, Fischer-Tropsch wax derived base oils,and other wax-derived hydroisomerized base oils may have useful pourpoints of about −20° C. or lower, and under some conditions may haveadvantageous pour points of about −25° C. or lower, with useful pourpoints of about −30° C. to about −40° C. or lower. Useful compositionsof Gas-to-Liquids (GTL) base oils, Fischer-Tropsch wax derived baseoils, and wax-derived hydroisomerized base oils are recited in U.S. Pat.Nos. 6,080,301; 6,090,989, and 6,165,949 for example, and areincorporated herein in their entirety by reference.

The hydrocarbyl aromatics can be used as a base oil or base oilcomponent and can be any hydrocarbyl molecule that contains at leastabout 5% of its weight derived from an aromatic moiety such as abenzenoid moiety or naphthenoid moiety, or their derivatives. Thesehydrocarbyl aromatics include alkyl benzenes, alkyl naphthalenes, alkyldiphenyl oxides, alkyl naphthols, alkyl diphenyl sulfides, alkylatedbis-phenol A, alkylated thiodiphenol, and the like. The aromatic can bemono-alkylated, dialkylated, polyalkylated, and the like. The aromaticcan be mono- or poly-functionalized. The hydrocarbyl groups can also becomprised of mixtures of alkyl groups, alkenyl groups, alkynyl,cycloalkyl groups, cycloalkenyl groups and other related hydrocarbylgroups. The hydrocarbyl groups can range from about C6 up to about C60with a range of about C8 to about C20 often being preferred. A mixtureof hydrocarbyl groups is often preferred, and up to about three suchsubstituents may be present. The hydrocarbyl group can optionallycontain sulfur, oxygen, and/or nitrogen containing substituents. Thearomatic group can also be derived from natural (petroleum) sources,provided at least about 5% of the molecule is comprised of an above-typearomatic moiety. Viscosities at 100° C. of approximately 3 cSt to about50 cSt are preferred, with viscosities of approximately 3.4 cSt to about20 cSt often being more preferred for the hydrocarbyl aromaticcomponent. In an embodiment, an alkyl naphthalene where the alkyl groupis primarily comprised of 1-hexadecene is used. Other alkylates ofaromatics can be advantageously used. Naphthalene or methyl naphthalene,for example, can be alkylated with olefins such as octene, decene,dodecene, tetradecene or higher, mixtures of similar olefins, and thelike. Useful concentrations of hydrocarbyl aromatic in a lubricant oilcomposition can be about 2% to about 25%, preferably about 4% to about20%, and more preferably about 4% to about 15%, depending on theapplication.

Alkylated aromatics such as the hydrocarbyl aromatics of the presentdisclosure may be produced by well-known Friedel-Crafts alkylation ofaromatic compounds. See Friedel-Crafts and Related Reactions, Olah, G.A. (ed.), Inter-science Publishers, New York, 1963. For example, anaromatic compound, such as benzene or naphthalene, is alkylated by anolefin, alkyl halide or alcohol in the presence of a Friedel-Craftscatalyst. See Friedel-Crafts and Related Reactions, Vol. 2, part 1,chapters 14, 17, and 18, See Olah, G. A. (ed.), Inter-sciencePublishers, New York, 1964. Many homogeneous or heterogeneous, solidcatalysts are known to one skilled in the art. The choice of catalystdepends on the reactivity of the starting materials and product qualityrequirements. For example, strong acids such as AlCl3, BF3, or HF may beused. In some cases, milder catalysts such as FeCl3 or SnCl4 arepreferred. Newer alkylation technology uses zeolites or solid superacids.

Esters comprise a useful base stock. Additive solvency and sealcompatibility characteristics may be secured by the use of esters suchas the esters of dibasic acids with monoalkanols and the polyol estersof monocarboxylic acids. Esters of the former type include, for example,the esters of dicarboxylic acids such as phthalic acid, succinic acid,alkyl succinic acid, alkenyl succinic acid, maleic acid, azelaic acid,suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic aciddimer, malonic acid, alkyl malonic acid, alkenyl malonic acid, etc.,with a variety of alcohols such as butyl alcohol, hexyl alcohol, dodecylalcohol, 2-ethylhexyl alcohol, etc. Specific examples of these types ofesters include dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexylfumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate,dioctyl phthalate, didecyl phthalate, dieicosyl sebacate, etc.

Particularly useful synthetic esters are those which are obtained byreacting one or more polyhydric alcohols, preferably the hinderedpolyols (such as the neopentyl polyols, e.g., neopentyl glycol,trimethylol ethane, 2-methyl-2-propyl-1,3-propanediol, trimethylolpropane, pentaerythritol and dipentaerythritol) with alkanoic acidscontaining at least about 4 carbon atoms, preferably C5 to C30 acidssuch as saturated straight chain fatty acids including caprylic acid,capric acid, lauric acid, myristic acid, palmitic acid, stearic acid,arachic acid, and behenic acid, or the corresponding branched chainfatty acids or unsaturated fatty acids such as oleic acid, or mixturesof any of these materials.

Suitable synthetic ester components include the esters of trimethylolpropane, trimethylol butane, trimethylol ethane, pentaerythritol and/ordipentaerythritol with one or more monocarboxylic acids containing fromabout 5 to about 10 carbon atoms. These esters are widely availablecommercially, for example, the Mobil P-41 and P-51 esters of ExxonMobilChemical Company.

Also useful are esters derived from renewable material such as coconut,palm, rapeseed, soy, sunflower and the like. These esters may bemonoesters, di-esters, polyol esters, complex esters, or mixturesthereof. These esters are widely available commercially, for example,the Mobil P-51 ester of ExxonMobil Chemical Company.

Other useful fluids of lubricating viscosity include non-conventional orunconventional base stocks that have been processed, preferablycatalytically, or synthesized to provide high performance lubricationcharacteristics.

Non-conventional or unconventional base stocks/base oils include one ormore of a mixture of base stock(s) derived from one or moreGas-to-Liquids (GTL) materials, as well as isomerate/isodewaxate basestock(s) derived from natural wax or waxy feeds, mineral and ornon-mineral oil waxy feed stocks such as slack waxes, natural waxes, andwaxy stocks such as gas oils, waxy fuels hydrocracker bottoms, waxyraffinate, hydrocrackate, thermal crackates, or other mineral, mineraloil, or even non-petroleum oil derived waxy materials such as waxymaterials received from coal liquefaction or shale oil, and mixtures ofsuch base stocks.

GTL materials are materials that are derived via one or more synthesis,combination, transformation, rearrangement, and/ordegradation/deconstructive processes from gaseous carbon-containingcompounds, hydrogen-containing compounds and/or elements as feed stockssuch as hydrogen, carbon dioxide, carbon monoxide, water, methane,ethane, ethylene, acetylene, propane, propylene, propyne, butane,butylenes, and butynes. GTL base stocks and/or base oils are GTLmaterials of lubricating viscosity that are generally derived fromhydrocarbons; for example, waxy synthesized hydrocarbons, that arethemselves derived from simpler gaseous carbon-containing compounds,hydrogen-containing compounds and/or elements as feed stocks. GTL basestock(s) and/or base oil(s) include oils boiling in the lube oil boilingrange (1) separated/fractionated from synthesized GTL materials such as,for example, by distillation and subsequently subjected to a final waxprocessing step which involves either or both of a catalytic dewaxingprocess, or a solvent dewaxing process, to produce lube oils ofreduced/low pour point; (2) synthesized wax isomerates, comprising, forexample, hydrodewaxed or hydroisomerized cat and/or solvent dewaxedsynthesized wax or waxy hydrocarbons; (3) hydrodewaxed orhydroisomerized cat and/or solvent dewaxed Fischer-Tropsch (F-T)material (i.e., hydrocarbons, waxy hydrocarbons, waxes and possibleanalogous oxygenates); preferably hydrodewaxed orhydroisomerized/followed by cat and/or solvent dewaxing dewaxed F-T waxyhydrocarbons, or hydrodewaxed or hydroisomerized/followed by cat (orsolvent) dewaxing dewaxed, F-T waxes, or mixtures thereof.

GTL base stock(s) and/or base oil(s) derived from GTL materials,especially, hydrodewaxed or hydroisomerized/followed by cat and/orsolvent dewaxed wax or waxy feed, preferably F-T material derived basestock(s) and/or base oil(s), are characterized typically as havingkinematic viscosities at 100° C. of from about 2 mm2/s to about 50 mm2/s(ASTM D445). They are further characterized typically as having pourpoints of −5° C. to about −40° C. or lower (ASTM D97). They are alsocharacterized typically as having viscosity indices of about 80 to about140 or greater (ASTM D2270).

In addition, the GTL base stock(s) and/or base oil(s) are typicallyhighly paraffinic (>90% saturates), and may contain mixtures ofmonocycloparaffins and multicycloparaffins in combination withnon-cyclic isoparaffins. The ratio of the naphthenic (i.e.,cycloparaffin) content in such combinations varies with the catalyst andtemperature used. Further, GTL base stock(s) and/or base oil(s)typically have very low sulfur and nitrogen content, generallycontaining less than about 10 ppm, and more typically less than about 5ppm of each of these elements. The sulfur and nitrogen content of GTLbase stock(s) and/or base oil(s) obtained from F-T material, especiallyF-T wax, is essentially nil. In addition, the absence of phosphorous andaromatics make this materially especially suitable for the formulationof low SAP products.

The term GTL base stock and/or base oil and/or wax isomerate base stockand/or base oil is to be understood as embracing individual fractions ofsuch materials of wide viscosity range as recovered in the productionprocess, mixtures of two or more of such fractions, as well as mixturesof one or two or more low viscosity fractions with one, two or morehigher viscosity fractions to produce a blend wherein the blend exhibitsa target kinematic viscosity.

The GTL material, from which the GTL base stock(s) and/or base oil(s)is/are derived is preferably an F-T material (i.e., hydrocarbons, waxyhydrocarbons, wax).

Base oils for use in the formulated lubricating oils useful in thepresent disclosure are any of the variety of oils corresponding to APIGroup I, Group II, Group III, Group IV, and Group V oils and mixturesthereof, preferably API Group II, Group III, Group IV, and Group V oilsand mixtures thereof, more preferably the Group III to Group V base oilsdue to their exceptional volatility, stability, viscometric andcleanliness features. Minor quantities of Group I stock, such as theamount used to dilute additives for blending into formulated lube oilproducts, can be tolerated but should be kept to a minimum, i.e. amountsonly associated with their use as diluent/carrier oil for additives usedon an “as-received” basis. Even in regard to the Group II stocks, it ispreferred that the Group II stock be in the higher quality rangeassociated with that stock, i.e. a Group II stock having a viscosityindex in the range 100<VI<120.

In certain embodiments of the present invention, the lubricantcomposition includes Group III base stocks. The utilized Group III basestocks are not particularly limited. Any base stocks which correspondsto API Group III can be used. Additionally, a single Group III basestock can be used, or multiple Group III base stocks can be used incombination.

In certain embodiments of the present invention, the Group III basestock is present as 10-90 wt % of the total weight of the lubricantcomposition. The Group III base stock is preferably present as 30-70 wt% of the total weight of the lubricant composition, and more preferably,the Group III base stock is present as 10-64.21 wt % of the total weightof the lubricant composition.

In certain embodiments of the present invention, the lubricatingcomposition includes Polyalphaolefin (PAO) oil base stocks. PAOs, whichare Group IV API base stocks, are a commonly used synthetic hydrocarbonoil. The PAOs of the present invention are not particularly limited. AnyPAOs can be used. A single PAO can be used, or multiple PAOs can be usedin combination.

In certain embodiments of the present invention, the PAOs are present asup to 60 wt % of the total weight of the lubricant composition. The PAOsare preferably present as 5-50 wt % of the total weight of the lubricantcomposition, and more preferably, the PAOs are present as 10-31.92 wt %of the total weight of the lubricant composition.

In certain embodiments of the present invention, a Group V co-base stockis included in the lubricant composition. For example, utilized Group Vco-base stocks may include esters, alkylated naphthalenes or mixturesthereof.

In certain embodiments of the present invention, the Group V co-basestock is present as 0-15 wt % of the total weight of the lubricantcomposition. The Group V co-base stock is preferably present as 0-10 wt% of the total weight of the lubricant composition, and more preferably,the Group V co-base stock is present as 5 wt % of the total weight ofthe lubricant composition.

Additives

In addition to the CRFM and any utilized base stocks, certainembodiments of the present invention may additionally contain one ormore of commonly used lubricating oil performance additives, whichinclude but are not limited to detergents, antiwear additives,dispersants, viscosity modifiers, corrosion inhibitors, rust inhibitors,metal deactivators, extreme pressure additives, anti-seizure agents, waxmodifiers, viscosity modifiers, fluid-loss additives, seal compatibilityagents, lubricity agents, anti-staining agents, chromophoric agents,defoamants, demulsifiers, emulsifiers, densifiers, wetting agents,gelling agents, tackiness agents, colorants, cleanliness boosters andothers. For a review of many commonly used additives, see Klamann inLubricants and Related Products, Verlag Chemie, Deerfield Beach, Fla.;ISBN 0-89573-177-0. Reference is also made to “Lubricant Additives” byM. W. Ranney, published by Noyes Data Corporation of Parkridge, N.J.(1973); see also U.S. Pat. No. 7,704,930, the disclosure of which isincorporated herein in its entirety. These additives are commonlydelivered with varying amounts of diluent oil, that may range from 5 wt% to 50 wt %.

The additives useful in this disclosure do not have to be soluble in thelubricant composition. Insoluble additives such as zinc stearate in oilcan be dispersed in the lubricant composition of this disclosure.

It is noted that many of the additives are shipped from the additivemanufacturer as a concentrate, containing one or more additivestogether, with a certain amount of base oil diluents.

The types and quantities of performance additives used in combinationwith the instant disclosure in lubricant compositions are not limited bythe examples shown herein as illustrations.

Dispersants

In some embodiments of the present invention, one or more dispersantsmay be included in the lubricant composition. During engine operation,oil-insoluble oxidation byproducts are produced. Dispersants help keepthese byproducts in solution, thus diminishing their deposition on metalsurfaces. Dispersants may be ashless or ash-forming in nature.Preferably, the dispersant is ashless. So called ashless dispersants areorganic materials that form substantially no ash upon combustion. Forexample, non-metal-containing or borated metal-free dispersants areconsidered ashless. In contrast, metal-containing detergents discussedabove form ash upon combustion.

Suitable dispersants typically contain a polar group attached to arelatively high molecular weight hydrocarbon chain. The polar grouptypically contains at least one element of nitrogen, oxygen, orphosphorus. Typical hydrocarbon chains contain 50 to 400 carbon atoms.

A particularly useful class of dispersants are the (poly)alkenylsuccinicderivatives, typically produced by the reaction of a long chainhydrocarbyl substituted succinic compound, usually a hydrocarbylsubstituted succinic anhydride, with a polyhydroxy or polyaminocompound. The long chain hydrocarbyl group constituting the oleophilicportion of the molecule which confers solubility in the oil, is normallya polyisobutylene group. Many examples of this type of dispersant arewell known commercially and in the literature. Exemplary U.S. patentsdescribing such dispersants are U.S. Pat. Nos. 3,172,892; 3,2145,707;3,219,666; 3,316,177; 3,341,542; 3,444,170; 3,454,607; 3,541,012;3,630,904; 3,632,511; 3,787,374 and 4,234,435. Other types of dispersantare described in U.S. Pat. Nos. 3,036,003; 3,200,107; 3,254,025;3,275,554; 3,438,757; 3,454,555; 3,565,804; 3,413,347; 3,697,574;3,725,277; 3,725,480; 3,726,882; 4,454,059; 3,329,658; 3,449,250;3,519,565; 3,666,730; 3,687,849; 3,702,300; 4,100,082; 5,705,458. Afurther description of dispersants may be found, for example, inEuropean Patent Application No. 471 071, to which reference is made forthis purpose.

Hydrocarbyl-substituted succinic acid and hydrocarbyl-substitutedsuccinic anhydride derivatives are useful dispersants. In particular,succinimide, succinate esters, or succinate ester amides prepared by thereaction of a hydrocarbon-substituted succinic acid compound preferablyhaving at least 50 carbon atoms in the hydrocarbon substituent, with atleast one equivalent of an alkylene amine are particularly useful.

Succinimides are formed by the condensation reaction between hydrocarbylsubstituted succinic anhydrides and amines. Molar ratios can varydepending on the polyamine. For example, the molar ratio of hydrocarbylsubstituted succinic anhydride to TEPA can vary from about 1:1 to about5:1. Representative examples are shown in U.S. Pat. Nos. 3,087,936;3,172,892; 3,219,666; 3,272,746; 3,322,670; and U.S. Pat. Nos.3,652,616, 3,948,800; and Canada Patent No. 1,094,044.

Succinate esters are formed by the condensation reaction betweenhydrocarbyl substituted succinic anhydrides and alcohols or polyols.Molar ratios can vary depending on the alcohol or polyol used. Forexample, the condensation product of a hydrocarbyl substituted succinicanhydride and pentaerythritol is a useful dispersant.

Succinate ester amides are formed by condensation reaction betweenhydrocarbyl substituted succinic anhydrides and alkanol amines. Forexample, suitable alkanol amines include ethoxylatedpolyalkylpolyamines, propoxylated polyalkylpolyamines andpolyalkenylpolyamines such as polyethylene polyamines. One example ispropoxylated hexamethylenediamine. Representative examples are shown inU.S. Pat. No. 4,426,305.

The molecular weight of the hydrocarbyl substituted succinic anhydridesused in the preceding paragraphs will typically range between 800 and2,500 or more. The above products can be post-reacted with variousreagents such as sulfur, oxygen, formaldehyde, carboxylic acids such asoleic acid. The above products can also be post reacted with boroncompounds such as boric acid, borate esters or highly borateddispersants, to form borated dispersants generally having from about 0.1to about 5 moles of boron per mole of dispersant reaction product.

Mannich base dispersants are made from the reaction of alkylphenols,formaldehyde, and amines. See U.S. Pat. No. 4,767,551, which isincorporated herein by reference. Process aids and catalysts, such asoleic acid and sulfonic acids, can also be part of the reaction mixture.Molecular weights of the alkylphenols range from 800 to 2,500.Representative examples are shown in U.S. Pat. Nos. 3,697,574;3,703,536; 3,704,308; 3,751,365; 3,756,953; 3,798,165; and 3,803,039.

Typical high molecular weight aliphatic acid modified Mannichcondensation products useful in this disclosure can be prepared fromhigh molecular weight alkyl-substituted hydroxyaromatics or HNR2group-containing reactants.

Hydrocarbyl substituted amine ashless dispersant additives are wellknown to one skilled in the art; see, for example, U.S. Pat. Nos.3,275,554; 3,438,757; 3,565,804; 3,755,433, 3,822,209, and 5,084,197.

Preferred dispersants include borated and non-borated succinimides,including those derivatives from mono-succinimides, bis-succinimides,and/or mixtures of mono- and bis-succinimides, wherein the hydrocarbylsuccinimide is derived from a hydrocarbylene group such aspolyisobutylene having a Mn of from about 500 to about 5000, or fromabout 1000 to about 3000, or about 1000 to about 2000, or a mixture ofsuch hydrocarbylene groups, often with high terminal vinylic groups.Other preferred dispersants include succinic acid-esters and amides,alkylphenol-polyamine-coupled Mannich adducts, their capped derivatives,and other related components.

Polymethacrylate or polyacrylate derivatives are another class ofdispersants. These dispersants are typically prepared by reacting anitrogen containing monomer and a methacrylic or acrylic acid esterscontaining 5-25 carbon atoms in the ester group. Representative examplesare shown in U.S. Pat. Nos. 2,100,993, and 6,323,164. Polymethacrylateand polyacrylate dispersants are normally used as multifunctionalviscosity modifiers. The lower molecular weight versions can be used aslubricant dispersants or fuel detergents.

Illustrative preferred dispersants useful in this disclosure includethose derived from polyalkenyl-substituted mono- or dicarboxylic acid,anhydride or ester, which dispersant has a polyalkenyl moiety with anumber average molecular weight of at least 900 and from greater than1.3 to 1.7, preferably from greater than 1.3 to 1.6, most preferablyfrom greater than 1.3 to 1.5, functional groups (mono- or dicarboxylicacid producing moieties) per polyalkenyl moiety (a medium functionalitydispersant). Functionality (F) can be determined according to thefollowing formula:

F=(SAP×Mn)/((112,200×A.I.)−(SAP×98))

wherein SAP is the saponification number (i.e., the number of milligramsof KOH consumed in the complete neutralization of the acid groups in onegram of the succinic-containing reaction product, as determinedaccording to ASTM D94); Mn is the number average molecular weight of thestarting olefin polymer; and A.I. is the percent active ingredient ofthe succinic-containing reaction product (the remainder being unreactedolefin polymer, succinic anhydride and diluent).

The polyalkenyl moiety of the dispersant may have a number averagemolecular weight of at least 900, suitably at least 1500, preferablybetween 1800 and 3000, such as between 2000 and 2800, more preferablyfrom about 2100 to 2500, and most preferably from about 2200 to about2400. The molecular weight of a dispersant is generally expressed interms of the molecular weight of the polyalkenyl moiety. This is becausethe precise molecular weight range of the dispersant depends on numerousparameters including the type of polymer used to derive the dispersant,the number of functional groups, and the type of nucleophilic groupemployed.

Polymer molecular weight, specifically Mn, can be determined by variousknown techniques. One convenient method is gel permeation chromatography(GPC), which additionally provides molecular weight distributioninformation (see W. W. Yau, J. J. Kirkland and D. D. Bly, “Modern SizeExclusion Liquid Chromatography”, John Wiley and Sons, New York, 1979).Another useful method for determining molecular weight, particularly forlower molecular weight polymers, is vapor pressure osmometry (e.g., ASTMD3592).

The polyalkenyl moiety in a dispersant preferably has a narrow molecularweight distribution (MWD), also referred to as polydispersity, asdetermined by the ratio of weight average molecular weight (Mw) tonumber average molecular weight (Mn). Polymers having a Mw/Mn of lessthan 2.2, preferably less than 2.0, are most desirable. Suitablepolymers have a polydispersity of from about 1.5 to 2.1, preferably fromabout 1.6 to about 1.8.

Suitable polyalkenes employed in the formation of the dispersantsinclude homopolymers, interpolymers or lower molecular weighthydrocarbons. One family of such polymers comprise polymers of ethyleneand/or at least one C3 to C2 alpha-olefin having the formula H2C=CHR1wherein R1 is a straight or branched chain alkyl radical comprising 1 to26 carbon atoms and wherein the polymer contains carbon-to-carbonunsaturation, and a high degree of terminal ethenylidene unsaturation.Preferably, such polymers comprise interpolymers of ethylene and atleast one alpha-olefin of the above formula, wherein R1 is alkyl of from1 to 18 carbon atoms, and more preferably is alkyl of from 1 to 8 carbonatoms, and more preferably still of from 1 to 2 carbon atoms.

Another useful class of polymers is polymers prepared by cationicpolymerization of monomers such as isobutene and styrene. Commonpolymers from this class include polyisobutenes obtained bypolymerization of a C4 refinery stream having a butene content of 35 to75% by wt., and an isobutene content of 30 to 60% by wt. A preferredsource of monomer for making poly-n-butenes is petroleum feedstreamssuch as Raffinate II. These feedstocks are disclosed in the art such asin U.S. Pat. No. 4,952,739. A preferred embodiment utilizespolyisobutylene prepared from a pure isobutylene stream or a Raffinate Istream to prepare reactive isobutylene polymers with terminal vinylideneolefins. Polyisobutene polymers that may be employed are generally basedon a polymer chain of from 1500 to 3000.

The dispersant(s) are preferably non-polymeric (e.g., mono- orbis-succinimides). Such dispersants can be prepared by conventionalprocesses such as disclosed in U.S. Patent Application Publication No.2008/0020950, the disclosure of which is incorporated herein byreference.

The dispersant(s) can be borated by conventional means, as generallydisclosed in U.S. Pat. Nos. 3,087,936, 3,254,025 and 5,430,105.

In some embodiments of the present invention, utilized dispersants mayinclude, for example, succinimide, polyolefin amide alkeneamine,ethylene capped succinimide, borated polyisobutylsuccinimide-polyamineor mixtures thereof.

In certain embodiments of the present invention, the dispersants arepresent as 1-12 wt % of the total weight of the lubricant composition.The dispersants are preferably present as 2-8 wt % of the total weightof the lubricant composition, and more preferably, the dispersants arepresent as 4.44-5.4 wt % of total weight of the lubricant composition.

As used herein, the dispersant concentrations are given on an “asdelivered” basis. Typically, the active dispersant is delivered with aprocess oil. The “as delivered” dispersant typically contains from about20 weight percent to about 80 weight percent, or from about 40 weightpercent to about 60 weight percent, of active dispersant in the “asdelivered” dispersant product.

Detergents

In certain embodiments of the present invention, detergents may beincluded in the lubricant composition. Illustrative detergents useful inthis disclosure include, for example, alkali metal detergents, alkalineearth metal detergents, or mixtures of one or more alkali metaldetergents and one or more alkaline earth metal detergents. A typicaldetergent is an anionic material that contains a long chain hydrophobicportion of the molecule and a smaller anionic or oleophobic hydrophilicportion of the molecule. The anionic portion of the detergent istypically derived from an organic acid such as a sulfur acid, carboxylicacid (e.g., salicylic acid), phosphorous acid, phenol, or mixturesthereof. The counterion is typically an alkaline earth or alkali metal.The detergent can be overbased as described herein.

The detergent is preferably a metal salt of an organic or inorganicacid, a metal salt of a phenol, or mixtures thereof. The metal ispreferably selected from an alkali metal, an alkaline earth metal, andmixtures thereof. The organic or inorganic acid is selected from analiphatic organic or inorganic acid, a cycloaliphatic organic orinorganic acid, an aromatic organic or inorganic acid, and mixturesthereof.

The metal is preferably selected from an alkali metal, an alkaline earthmetal, and mixtures thereof. More preferably, the metal is selected fromcalcium (Ca), magnesium (Mg), and mixtures thereof.

The organic acid or inorganic acid is preferably selected from a sulfuracid, a carboxylic acid, a phosphorus acid, and mixtures thereof.

Preferably, the metal salt of an organic or inorganic acid or the metalsalt of a phenol comprises calcium phenate, calcium sulfonate, calciumsalicylate, magnesium phenate, magnesium sulfonate, magnesiumsalicylate, an overbased detergent, and mixtures thereof.

Salts that contain a substantially stochiometric amount of the metal aredescribed as neutral salts and have a total base number (TBN, asmeasured by ASTM D2896) of from 0 to 80. Many compositions areoverbased, containing large amounts of a metal base that is achieved byreacting an excess of a metal compound (a metal hydroxide or oxide, forexample) with an acidic gas (such as carbon dioxide). Useful detergentscan be neutral, mildly overbased, or highly overbased. These detergentscan be used in mixtures of neutral, overbased, highly overbased calciumsalicylate, sulfonates, phenates and/or magnesium salicylate,sulfonates, phenates. The TBN ranges can vary from low, medium to highTBN products, including as low as 0 to as high as 600. Mixtures of low,medium, high TBN can be used, along with mixtures of calcium andmagnesium metal based detergents, and including sulfonates, phenates,salicylates, and carboxylates. A detergent mixture with a metal ratio of1, in conjunction of a detergent with a metal ratio of 2, and as high asa detergent with a metal ratio of 5, can be used. Borated detergents canalso be used.

Alkaline earth phenates are another useful class of detergent. Thesedetergents can be made by reacting alkaline earth metal hydroxide oroxide (CaO, Ca(OH)2, BaO, Ba(OH)2, MgO, Mg(OH)2, for example) with analkyl phenol or sulfurized alkylphenol. Useful alkyl groups includestraight chain or branched C1-C30 alkyl groups, preferably, C4-C20 ormixtures thereof. Examples of suitable phenols include isobutylphenol,2-ethylhexylphenol, nonylphenol, dodecyl phenol, and the like. It shouldbe noted that starting alkylphenols may contain more than one alkylsubstituent that are each independently straight chain or branched andcan be used from 0.5 to 6 weight percent. When a non-sulfurizedalkylphenol is used, the sulfurized product may be obtained by methodswell known in the art. These methods include heating a mixture ofalkylphenol and sulfurizing agent (including elemental sulfur, sulfurhalides such as sulfur dichloride, and the like) and then reacting thesulfurized phenol with an alkaline earth metal base.

In accordance with this disclosure, metal salts of carboxylic acids arepreferred detergents. These carboxylic acid detergents may be preparedby reacting a basic metal compound with at least one carboxylic acid andremoving free water from the reaction product. These compounds may beoverbased to produce the desired TBN level. Detergents made fromsalicylic acid are one preferred class of detergents derived fromcarboxylic acids. Useful salicylates include long chain alkylsalicylates. One useful family of compositions is of the formula

where R is an alkyl group having 1 to about 30 carbon atoms, n is aninteger from 1 to 4, and M is an alkaline earth metal. Preferred Rgroups are alkyl chains of at least C11, preferably C13 or greater. Rmay be optionally substituted with substituents that do not interferewith the detergent's function. M is preferably, calcium, magnesium, orbarium. More preferably, M is calcium.

Hydrocarbyl-substituted salicylic acids may be prepared from phenols bythe Kolbe reaction (see U.S. Pat. No. 3,595,791). The metal salts of thehydrocarbyl-substituted salicylic acids may be prepared by doubledecomposition of a metal salt in a polar solvent such as water oralcohol.

Alkaline earth metal phosphates are also used as detergents and areknown in the art.

Detergents may be simple detergents or what is known as hybrid orcomplex detergents. The latter detergents can provide the properties oftwo detergents without the need to blend separate materials. See U.S.Pat. No. 6,034,039.

In some embodiments of the present invention, utilized detergents mayinclude, for example, highly overbased calcium salicylate, low basecalcium salicylate, overbased magnesium sulfonate, neutral calciumsulfonate or mixtures thereof.

In certain embodiments of the present invention, the detergents arepresent as 1-8 wt % of the total weight of the lubricant composition.The detergents are preferably present as 1-5 wt % of the total weight ofthe lubricant composition, and more preferably, the detergents arepresent as 2.03-3.83 wt % of total weight of the lubricant composition.

As used herein, the detergent concentrations are given on an “asdelivered” basis. Typically, the active detergent is delivered with aprocess oil. The “as delivered” detergent typically contains from about20 weight percent to about 100 weight percent, or from about 40 weightpercent to about 60 weight percent, of active detergent in the “asdelivered” detergent product.

Friction Modifiers

In certain embodiments of the present invention, the lubricantcomposition may include additional friction modifiers. Illustrativefriction modifiers may include, for example, organometallic compounds ormaterials, or mixtures thereof. Illustrative organometallic frictionmodifiers useful in the lubricating engine oil formulations of thisdisclosure include, for example, molybdenum amine, molybdenum diamine,an organotungstenate, a molybdenum dithiocarbamate, molybdenumdithiophosphates, molybdenum amine complexes, molybdenum carboxylates,and the like, and mixtures thereof. Similar tungsten based compounds maybe preferable.

Other illustrative friction modifiers useful in the lubricating engineoil formulations of this disclosure include, for example, alkoxylatedfatty acid esters, alkanolamides, polyol fatty acid esters, boratedglycerol fatty acid esters, fatty alcohol ethers, and mixtures thereof.

Illustrative alkoxylated fatty acid esters include, for example,polyoxyethylene stearate, fatty acid polyglycol ester, and the like.These can include polyoxypropylene stearate, polyoxybutylene stearate,polyoxyethylene isosterate, polyoxypropylene isostearate,polyoxyethylene palmitate, and the like.

Illustrative alkanolamides include, for example, lauric aciddiethylalkanolamide, palmic acid diethylalkanolamide, and the like.These can include oleic acid diethyalkanolamide, stearic aciddiethylalkanolamide, oleic acid diethylalkanolamide, polyethoxylatedhydrocarbylamides, polypropoxylated hydrocarbylamides, and the like.

Illustrative polyol fatty acid esters include, for example, glycerolmono-oleate, saturated mono-, di-, and tri-glyceride esters, glycerolmono-stearate, and the like. These can include polyol esters,hydroxyl-containing polyol esters, and the like.

Illustrative borated glycerol fatty acid esters include, for example,borated glycerol mono-oleate, borated saturated mono-, di-, andtri-glyceride esters, borated glycerol mono-sterate, and the like. Inaddition to glycerol polyols, these can include trimethylolpropane,pentaerythritol, sorbitan, and the like. These esters can be polyolmonocarboxylate esters, polyol dicarboxylate esters, and on occasionpolyoltricarboxylate esters. Preferred can be the glycerol mono-oleates,glycerol dioleates, glycerol trioleates, glycerol monostearates,glycerol distearates, and glycerol tristearates and the correspondingglycerol monopalmitates, glycerol dipalmitates, and glyceroltripalmitates, and the respective isostearates, linoleates, and thelike. On occasion the glycerol esters can be preferred as well asmixtures containing any of these. Ethoxylated, propoxylated, butoxylatedfatty acid esters of polyols, especially using glycerol as underlyingpolyol can be preferred.

Illustrative fatty alcohol ethers include, for example, stearyl ether,myristyl ether, and the like. Alcohols, including those that have carbonnumbers from C3 to C50, can be ethoxylated, propoxylated, or butoxylatedto form the corresponding fatty alkyl ethers. The underlying alcoholportion can preferably be stearyl, myristyl, C11-C13 hydrocarbon, oleyl,isosteryl, and the like.

The lubricating oils of this disclosure exhibit desired properties,e.g., wear control, in the presence or absence of a friction modifier.

Concentrations of molybdenum-containing materials are often described interms of Mo metal concentration. Advantageous concentrations of Mo mayrange from 25 ppm to 700 ppm or more, and often with a preferred rangeof 50-200 ppm. Friction modifiers of all types may be used alone or inmixtures with the materials of this disclosure. Often mixtures of two ormore friction modifiers, or mixtures of friction modifier(s) withalternate surface active material(s), are also desirable.

In certain embodiments of the present invention, friction modifiers, inaddition to the amount of CRFM, may be present as 0-1 wt % of the totalweight of the lubricant composition. The friction modifiers, in additionto the amount of CRFM, are preferably present as 0-0.6 wt % of the totalweight of the lubricant composition, and more preferably, the frictionmodifiers, in addition to the amount of CRFM, are present as 0.2-0.4 wt% of total weight of the lubricant composition.

Viscosity Modifiers

In some embodiments of the present invention, viscosity modifiers, alsoknown as viscosity index improvers (VI improvers), and viscosityimprovers, can be included in the lubricant composition.

Viscosity modifiers provide lubricants with high and low temperatureoperability. These additives impart shear stability at elevatedtemperatures and acceptable viscosity at low temperatures.

Suitable viscosity modifiers include high molecular weight hydrocarbons,polyesters and viscosity modifier dispersants that function as both aviscosity modifier and a dispersant. Typical molecular weights of thesepolymers are between about 10,000 to 1,500,000, more typically about20,000 to 1,200,000, and even more typically between about 50,000 and1,000,000.

Examples of suitable viscosity modifiers are linear or star-shapedpolymers and copolymers of methacrylate, butadiene, olefins, oralkylated styrenes. Polyisobutylene is a commonly used viscositymodifier. Another suitable viscosity modifier is polymethacrylate(copolymers of various chain length alkyl methacrylates, for example),some formulations of which also serve as pour point depressants. Othersuitable viscosity modifiers include copolymers of ethylene andpropylene, hydrogenated block copolymers of styrene and isoprene, andpolyacrylates (copolymers of various chain length acrylates, forexample). Specific examples include styrene-isoprene orstyrene-butadiene based polymers of 50,000 to 200,000 molecular weight.

Olefin copolymers are commercially available from Chevron OroniteCompany LLC under the trade designation “PARATONE®” (such as “PARATONE®8921” and “PARATONE® 8941”); from Afton Chemical Corporation under thetrade designation “HiTEC®” (such as “HiTEC® 5850B”; and from TheLubrizol Corporation under the trade designation “Lubrizol® 7067C”.Hydrogenated polyisoprene star polymers are commercially available fromInfineum International Limited, e.g., under the trade designation“SV200” and “SV600”. Hydrogenated diene-styrene block copolymers arecommercially available from Infineum International Limited, e.g., underthe trade designation “SV 50”.

The polymethacrylate or polyacrylate polymers can be linear polymerswhich are available from Evnoik Industries under the trade designation“Viscoplex®” (e.g., Viscoplex 6-954) or star polymers which areavailable from Lubrizol Corporation under the trade designation Asteric™(e.g., Lubrizol 87708 and Lubrizol 87725).

Illustrative vinyl aromatic-containing polymers useful in thisdisclosure may be derived predominantly from vinyl aromatic hydrocarbonmonomer. Illustrative vinyl aromatic-containing copolymers useful inthis disclosure may be represented by the following general formula:

A-B

wherein A is a polymeric block derived predominantly from vinyl aromatichydrocarbon monomer, and B is a polymeric block derived predominantlyfrom conjugated diene monomer.

In certain embodiments of the present invention, viscosity modifiers maybe present as 1-12 wt % of the total weight of the lubricantcomposition. The viscosity modifiers are preferably present as 3-8 wt %of the total weight of the lubricant composition, and more preferably,the viscosity modifiers are present as 5.6-6.4 wt % of total weight ofthe lubricant composition. Viscosity modifiers are typically added asconcentrates, in large amounts of diluent oil.

As used herein, the viscosity modifier concentrations are given on an“as delivered” basis. Typically, the active polymer is delivered with adiluent oil. The “as delivered” viscosity modifier typically containsfrom 20 weight percent to 75 weight percent of an active polymer forpolymethacrylate or polyacrylate polymers, or from 8 weight percent to20 weight percent of an active polymer for olefin copolymers,hydrogenated polyisoprene star polymers, or hydrogenated diene-styreneblock copolymers, in the “as delivered” polymer concentrate.

Cleanliness Boosters

In certain embodiments of the present invention, the lubricantcomposition includes cleanliness boosters. The cleanliness boosters ofthe present invention are not particularly limited. Any cleanlinessboosters can be used. A single cleanliness booster can be used, ormultiple cleanliness boosters can be used in combination. Cleanlinessboosters refer to a broad class of commercially available componentsused to reduce hard carbonaceous deposits that form on the piston landand groove surfaces of diesel engines due to degradation of the base oiland oil additives under extremely high temperatures. Keeping an enginefree of deposits is highly desirable as the deposits in an engine reduceeffective heat transfer, contribute to friction, and change the highlyengineered clearances of a modern engine which can result is wear.Cleanliness is difficult to achieve in a modern engine oil formulationdue to limits placed on ash containing componentry (e.g., overbaseddetergents) which are used to prevent formation of deposits. These ashlimits are in place to reduce blockage of diesel particulate filters andlimit the amount of an overbased detergent that may be used in a givenengine oil formulation. One method of overcoming this limit is throughthe use of ashless cleanliness boosters. Some of these materials whichare commercially available include alkyl phenol ether polymers,polyisobutylene polymers and ashless detergent chemistries. Thesematerials are typically used in a formulation in a range from 0.5-2.0 wt% and provide a modest but consistent improvement in cleanliness, inparticular in the VW PV1452 TDi-2 Deposit Test (CEC L-078-99) which isused in multiple ACEA and OEM claims. This cleanliness boost can rangefrom 1-5 piston deposit merits in the VW PV1452 test depending ondepending on specific chemistry selected, formulation, and treat rate.According to certain exemplary embodiments of the invention, thecleanliness booster may include alkyl phenol ether polymer (DB2),polyisobutylene or a combination thereof.

In certain embodiments of the present invention, cleanliness boostersmay be present as 0.5-3 wt % of the total weight of the lubricantcomposition. The cleanliness boosters are preferably present as 0.5-1.5wt % of the total weight of the lubricant composition, and morepreferably, the cleanliness boosters are present as 1 wt % of totalweight of the lubricant composition.

Antiwear

In some embodiments of the present invention, antiwear additives may beincluded in the lubricant composition. Illustrative antiwear additivesuseful in this disclosure include, for example, metal salts of acarboxylic acid. The metal is selected from a transition metal andmixtures thereof. The carboxylic acid is selected from an aliphaticcarboxylic acid, a cycloaliphatic carboxylic acid, an aromaticcarboxylic acid, and mixtures thereof.

The metal is preferably selected from a Group 10, 11 and 12 metal, andmixtures thereof. The carboxylic acid is preferably an aliphatic,saturated, unbranched carboxylic acid having from about 8 to about 26carbon atoms, and mixtures thereof.

The metal is preferably selected from nickel (Ni), palladium (Pd),platinum (Pt), copper (Cu), silver (Ag), gold (Au), zinc (Zn), cadium(Cd), mercury (Hg), and mixtures thereof.

The carboxylic acid is preferably selected from caprylic acid (C8),pelargonic acid (C9), capric acid (C10), undecylic acid (C11), lauricacid (C12), tridecylic acid (C13), myristic acid (C14), pentadecylicacid (C15), palmitic acid (C16), margaric acid (C17), stearic acid(C18), nonadecylic acid (C19), arachidic acid (C20), heneicosylic acid(C21), behenic acid (C22), tricosylic acid (C23), lignoceric acid (C24),pentacosylic acid (C25), cerotic acid (C26), and mixtures thereof.

Preferably, the metal salt of a carboxylic acid comprises zinc stearate,silver stearate, palladium stearate, zinc palmitate, silver palmitate,palladium palmitate, and mixtures thereof.

The metal salt of a carboxylic acid is present in the engine oilformulations of this disclosure in an amount of from about 0.01 weightpercent to about 5 weight percent, based on the total weight of theformulated oil.

Low phosphorus engine oil formulations are included in this disclosure.For such formulations, the phosphorus content is typically less thanabout 0.12 weight percent preferably less than about 0.10 weight percentand most preferably less than about 0.085 weight percent.

A metal alkylthiophosphate and more particularly a metal dialkyl dithiophosphate in which the metal constituent is zinc, or zinc dialkyl dithiophosphate (ZDDP) can be a useful component of the lubricating oils ofthis disclosure. ZDDP can be derived from primary alcohols, secondaryalcohols or mixtures thereof. ZDDP compounds generally are of theformula

Zn[SP(S)(OR1)(OR2)]2

where R1 and R2 are C1-C18 alkyl groups, preferably C2-C12 alkyl groups.These alkyl groups may be straight chain or branched. Alcohols used inthe ZDDP can be 2-propanol, butanol, secondary butanol, pentanols,hexanols such as 4-methyl-2-pentanol, n-hexanol, n-octanol, 2-ethylhexanol, alkylated phenols, and the like. Mixtures of secondary alcoholsor of primary and secondary alcohol can be preferred. Alkyl aryl groupsmay also be used.

Preferable zinc dithiophosphates which are commercially availableinclude secondary zinc dithiophosphates such as those available from forexample, The Lubrizol Corporation under the trade designations “LZ677A”, “LZ 1095” and “LZ 1371”, from for example Chevron Oronite underthe trade designation “OLOA 262” and from for example Afton Chemicalunder the trade designation “HITEC 7169”.

Low phosphorus engine oil formulations are included in this disclosure.For such formulations, the phosphorus content is typically less thanabout 0.12 weight percent preferably less than about 0.10 weight percentand most preferably less than about 0.085 weight percent.

Antioxidants

In some embodiments of the present invention, antioxidants may beincluded in the lubricant composition. Antioxidants retard the oxidativedegradation of base oils during service. Such degradation may result indeposits on metal surfaces, the presence of sludge, or a viscosityincrease in the lubricant. One skilled in the art knows a wide varietyof oxidation inhibitors that are useful in lubricating oil compositions.See, Klamann in Lubricants and Related Products, op cite, and U.S. Pat.Nos. 4,798,684 and 5,084,197, for example.

Useful antioxidants include hindered phenols. These phenolicantioxidants may be ashless (metal-free) phenolic compounds or neutralor basic metal salts of certain phenolic compounds. Typical phenolicantioxidant compounds are the hindered phenolics which are the oneswhich contain a sterically hindered hydroxyl group, and these includethose derivatives of dihydroxy aryl compounds in which the hydroxylgroups are in the o- or p-position to each other. Typical phenolicantioxidants include the hindered phenols substituted with C6+ alkylgroups and the alkylene coupled derivatives of these hindered phenols.Examples of phenolic materials of this type 2-t-butyl-4-heptyl phenol;2-t-butyl-4-octyl phenol; 2-t-butyl-4-dodecyl phenol;2,6-di-t-butyl-4-heptyl phenol; 2,6-di-t-butyl-4-dodecyl phenol;2-methyl-6-t-butyl-4-heptyl phenol; and 2-methyl-6-t-butyl-4-dodecylphenol. Other useful hindered mono-phenolic antioxidants may include forexample hindered 2,6-di-alkyl-phenolic proprionic ester derivatives.Bis-phenolic antioxidants may also be advantageously used in combinationwith the instant disclosure. Examples of ortho-coupled phenols include:2,2′-bis(4-heptyl-6-t-butyl-phenol); 2,2′-bis(4-octyl-6-t-butyl-phenol);and 2,2′-bis(4-dodecyl-6-t-butyl-phenol). Para-coupled bisphenolsinclude for example 4,4′-bis(2,6-di-t-butyl phenol) and4,4′-methylene-bis(2,6-di-t-butyl phenol).

Effective amounts of one or more catalytic antioxidants may also beused. The catalytic antioxidants comprise an effective amount of a) oneor more oil soluble polymetal organic compounds; and, effective amountsof b) one or more substituted N,N′-diaryl-o-phenylenediamine compoundsor c) one or more hindered phenol compounds; or a combination of both b)and c). Catalytic antioxidants are more fully described in U.S. Pat. No.8,048,833, herein incorporated by reference in its entirety.

Non-phenolic oxidation inhibitors which may be used include aromaticamine antioxidants and these may be used either as such or incombination with phenolics. Typical examples of non-phenolicantioxidants include: alkylated and non-alkylated aromatic amines suchas aromatic monoamines of the formula R8R9R10N where R8 is an aliphatic,aromatic or substituted aromatic group, R9 is an aromatic or asubstituted aromatic group, and R10 is H, alkyl, aryl or R11S(O)XR12where R11 is an alkylene, alkenylene, or aralkylene group, R12 is ahigher alkyl group, or an alkenyl, aryl, or alkaryl group, and x is 0, 1or 2. The aliphatic group R8 may contain from 1 to about 20 carbonatoms, and preferably contains from about 6 to 12 carbon atoms. Thealiphatic group is a saturated aliphatic group. Preferably, both R8 andR9 are aromatic or substituted aromatic groups, and the aromatic groupmay be a fused ring aromatic group such as naphthyl. Aromatic groups R8and R9 may be joined together with other groups such as S.

Typical aromatic amines antioxidants have alkyl substituent groups of atleast about 6 carbon atoms. Examples of aliphatic groups include hexyl,heptyl, octyl, nonyl, and decyl. Generally, the aliphatic groups willnot contain more than about 14 carbon atoms. The general types of amineantioxidants useful in the present compositions include diphenylamines,phenyl naphthylamines, phenothiazines, imidodibenzyls and diphenylphenylene diamines. Mixtures of two or more aromatic amines are alsouseful. Polymeric amine antioxidants can also be used. Particularexamples of aromatic amine antioxidants useful in the present disclosureinclude: p,p′-dioctyldiphenylamine; t-octylphenyl-alpha-naphthylamine;phenyl-alphanaphthylamine; and p-octylphenyl-alpha-naphthylamine.

Sulfurized alkyl phenols and alkali or alkaline earth metal saltsthereof also are useful antioxidants.

Pour Point Depressants (PPDs)

In some embodiments of the present invention, conventional pour pointdepressants, also known as lube oil flow improvers, may be included inthe lubricant composition. These pour point depressants may be added tolubricating compositions of the present disclosure to lower the minimumtemperature at which the fluid will flow or can be poured. Examples ofsuitable pour point depressants include polymethacrylates,polyacrylates, polyarylamides, condensation products of haloparaffinwaxes and aromatic compounds, vinyl carboxylate polymers, andterpolymers of dialkylfumarates, vinyl esters of fatty acids and allylvinyl ethers. U.S. Pat. Nos. 1,815,022; 2,015,748; 2,191,498; 2,387,501;2,655, 479; 2,666,746; 2,721,877; 2,721,878; and 3,250,715 describeuseful pour point depressants and/or the preparation thereof.

Seal Compatibility Agents

In certain embodiments of the present invention, seal compatibilityagents may be included in the lubricant composition. Seal compatibilityagents help to swell elastomeric seals by causing a chemical reaction inthe fluid or physical change in the elastomer. Suitable sealcompatibility agents for lubricating oils include organic phosphates,aromatic esters, aromatic hydrocarbons, esters (butylbenzyl phthalate,for example), and polybutenyl succinic anhydride.

Antifoam Agents

In certain embodiments of the present invention, antifoam agents may beincluded in the lubricant composition. These agents retard the formationof stable foams. Silicones and organic polymers are typical anti-foamagents. For example, polysiloxanes, such as silicon oil or polydimethylsiloxane, provide antifoam properties.

Inhibitors and Antirust Additives

In certain embodiments of the present invention, antirust additives maybe included in the lubricant composition. Antirust additives (orcorrosion inhibitors) are additives that protect lubricated metalsurfaces against chemical attack by water or other contaminants. A widevariety of these are commercially available.

One type of antirust additive is a polar compound that wets the metalsurface preferentially, protecting it with a film of oil. Another typeof antirust additive absorbs water by incorporating it in a water-in-oilemulsion so that only the oil touches the metal surface. Yet anothertype of antirust additive chemically adheres to the metal to produce anon-reactive surface. Examples of suitable additives include zincdithiophosphates, metal phenolates, basic metal sulfonates, fatty acidsand amines.

EXAMPLES

The following non-limiting examples are provided to illustrate thedisclosure.

Example I

A lubricant composition consistent with an embodiment of the presentinvention was prepared and labeled as composition 1B. See Table 2 belowfor a listing of the components of composition 1B. For comparison,composition 1A was prepared, and a listing of the components forcomposition 1A is also listed in Table 2 below. Composition 1A is asimilar composition that lacks a CRFM. Accordingly, composition 1A lacksthe complex chemical interactions between the blend of additives and theCRFM which support the sustained fuel economy of the lubricantcomposition of the present invention.

TABLE 2 1A 1B wt % wt % Base stocks polyalphaolefin 33.34 31.92 GroupIII Base stock A 30 30 Group III Base stock B 10 10 Ester Co-base stock5 5 Other Includes antioxidants, antiwear, 3.29 3.29 Additives pourpoint depressents, inorganic friction modifiers, antifoams and sealswell agents Cleanliness Cleanliness Booster 0 1 Booster ConventionalConventional Organic Friction 0.52 0 Organic Modifier Friction ModifierDetergents Calcium Salicylate Detergent 3 3 Magnesium Sulfonate 0.830.83 Detergent Viscosity Hydrogenated isoprene star 6.1 5.6 Modifierpolymer Dispersant Borated PIBSA/PAM dispersant 1.3 0 SuccinimideDispersant 6.62 5.4 CRFM Low-ash dispersant-stabilized 0 3.96 boratedfriction modifier (high stabilizer) Summary Table CRFM None 3.96%Co-Base stock Ester Ester Base stocks Highly Highly ParaffinicParaffinic

Composition 1A and 1B were tested on a highly instrumented FordEcoBoost® GTDI 2.0 L 4-cylinder engine mounted on an engine test stand.This test engine was a 4 valve-per-cylinder, dual overhead camshaftengine with continuous dual variable valve timing. The lubricationsystem of the engine was altered by adding an external oil cooler at theoil filter outlet. The oil cooler was externally fed with conditionedand temperature controlled water that was used to maintain the oiltemperature. An external coolant conditioner was used in place of awater pump to maintain constant consistent operating conditions. Aninline torque meter was used to calculate brake specific fuelconsumption (BSFC). Fuel temperature and pressure were strictlycontrolled, and a coriolis fuel flow meter was used to measure fuel flowinto the engine.

The BSFC of the engine was measured using an inline torque meter as afunction of time at five steady state operating points spanningdifferent engine speeds and break mean effective pressures (BMEP). Thesesteady state operating points corresponded to 1500 RPM and 3.0 bar BMEP,2000 RPM and 2.0 bar BMEP, 2000 RPM and 5.0 bar BMEP, 3000 RPM and 3.0Bar BMEP, and 4000 RPM and 5.0 bar BMEP. Each measurement of BSFC wasrepeated independently at least three times to establish statisticalconfidence.

Mileage accumulation was performed on the engine by continuallyrepeating the following one hour test cycle: 3 minutes at 2000 RPM and 2bar (45 mph in 4th gear), 1 minute ramp time, 20 minutes at 1700 RPM and7.5 bar (65 mph in 6th gear), 1 minute ramp time, 20 minutes at 1900 RPMand 8.5 bar (75 mph in 6th gear), 1 minute ramp time, 10 minutes at 1800RPM and 8.1 bar (70 mph in 6th gear), 1 minute ramp time, and 3 minutesat 2000 RPM and 2 bar (45 mph in 4th gear). BSFC was measured on freshoil and after every 2500 miles of oil aging through 10,000 miles. Thetesting was preformed on both composition 1A and composition 1B. Theobtained results for these tests were analyzed and compared.

Table 3 below lists the calculated percent reduction in BMEP after10,000 miles for composition 1A and composition 1B at the various steadystate operating points.

TABLE 3 % Reduction in BMEP After 10000 Miles 1A 1B 1500 rpm & 3 barBMEP 0.37 1.09 2000 rpm & 2 bar BMEP 0.19 1.81 2000 rpm & 5 bar BMEP0.05 0.74 3000 rpm & 3 bar BMEP 0.24 0.65 4000 rpm & 5 bar BMEP 0.710.62

Both compositions 1A and 1B show improved fuel consumption after 10,000miles at the high speed steady state operating point of 4000 RPM and 5.0bar BMEP. This is due to a drop in viscosity of the oil due to fueldilution and shear of the viscosity modifier. Such a result would beexpected, since engines at high speed operate in the hydrodynamic regimeof lubrication where surface contact is minimal and friction modifiersare ineffective. However, only composition 1B shows significantimprovement at low speed, where boundary and mixed regimes oflubrication occur. In these lubrication regimes, friction modifiers canbe very effective at reducing energy loss and therefore reducing theamount of fuel consumed for a given engine output. This effect isparticularly evident at the steady state load condition of 2000 RPM and2.0 bar BMEP.

The following discussion is made with reference to FIG. 1, whichillustrates the aging profile of compositions 1A and 1B for the 2000 RPMand 2.0 bar BMEP steady state operating point from 0 through 10,000miles. The results in FIG. 1 demonstrate the fuel efficiency changesthat result from the activation of the CRFM in an exemplary compositionof the present invention, the composition containing a low-ashdispersant-stabilized borated controlled release friction modifier. Atthe steady state load condition of 2000 RPM and 2.0 bar BMEP after10,000 miles of aging, composition 1B shows a reduction of fuelconsumption of 1.81% compared to its fresh oil value. At this same loadcondition, comparative composition 1A showed only a reduction of fuelconsumption of 0.19% compared to its fresh oil value. In other words,composition 1B, which is consistent which an embodiment of the presentinvention, under the conditions described above, demonstrated areduction of fuel consumption that was over nine times the amount ofreduction seen in the comparative composition. Accordingly, acomposition of an embodiment of the present invention shows significantand sustained fuel efficiency improvements over a comparativecomposition.

Example II

A lubricant composition consistent with an embodiment of the presentinvention was prepared and labeled as composition 2B. See Table 4 belowfor a listing of the components of composition 2B. For comparison,composition 2A was prepared, and a listing of the components forcomposition 2A also listed in Table 4. Composition 2A is a similarcomposition that lacks a CRFM. Accordingly, composition 2A lacks thecomplex chemical interactions between the blend of additives and theCRFM, which support the sustained fuel economy of the lubricantcomposition of the present invention.

TABLE 4 2A 2B wt % wt % Base stocks polyalphaolefin 10 10 Group III Basestock A 53.61 52.21 Group III Base stock B 12 12 Alkylated Naphthalene 55 Other Additives Includes antioxidants, antiwear, 2.96 2.96 pour pointdepressents, inorganic friction modifiers, antifoams and seal swellagents Conventional Conventional Organic Friction 0.5 0 Organic FrictionModifier Modifier Detergents Calcium Sulfonate 1.15 1.15 MagnesiumSulfonate 0.88 0.88 Viscosity Modifier Hydrogenated isoprene star 6.26.4 polymer Cleanliness Cleanliness Booster 0.5 1 Booster DispersantBorated PIBSA/PAM dispersant 1.2 0.74 Succinimide Dispersant 6 3.7 CRFMLow-ash dispersant-stabilized 0 3.96 borated friction modifier (highstabilizer) Summary Table CRFM None 3.96% Co-Base stock AlkylatedAlkylated Naphthalene Naphthalene Base stocks Highly Highly ParaffinicParaffinic

This testing was performed to demonstrate that the fuel economy benefitsshown in the instrumented engine test stand running steady stateoperating points could be observed in a full chassis dynamometer runningthe EPA FTP-75 test and the EPA Highway Fuel Economy Test. Compositions2A and 2B were tested by making aged oil fuel economy measurements ontwo equivalent 2016 model year Toyota Camrys with 3.5 L V-6 port fuelinjected engines and automatic transmissions. These two cars werepurchased new and were run for 200 miles before their use in the testingprocedure. Each car received triplicate checkout emissions measurementsover the requirements of EPA Federal Test Procedure 75 (FTP-75) and EPAHighway Fuel Economy Test (HwFET) using 87 octane regular unleadedgasoline to ensure the cars chosen were matched with similarperformance. All fuel economy measurements were performed on the sameHoriba 48-inch single roll chassis dynamometer. The tested compositionswere aged by removing the cars from the measurement dynamometer andplacing them on a mileage accumulation dynamometer, where the HwFETdrive cycle was run continuously with an average speed of approximately48 miles per hour. Then, the cars were put back on the measurementdynamometer after every 5000 mile aging cycle, were FTP-75 and HwFETmeasurements were performed to establish vehicle fuel economy. Each setof FTP-75 and HwFET measurements was repeated at least 3 times toestablish confidence. Minimal lubricant sampling was performed for oilanalysis and no oil top-up was conducted to maintain a steady volume.The results of this testing were then collected and analyzed.

The following discussion is made with reference to FIG. 2, whichillustrates the fuel economy change calculated for compositions 2A and2B over the course of a 15,000 mile aging cycle. Comparative composition2B shows a decrease in fuel economy of approximately 0.2 mpg over 15000miles. On the other hand, composition 2B, which is consistent with anembodiment of the present invention, surprisingly shows an increase infuel economy of approximately 0.2 mpg over 15000 miles, as measured bythese test protocols. This result is unexpected because an aged oilcomposition is generally expected to be less able to deliver fueleconomy than a new oil composition, which contains a full load offriction modifier. Friction modifier is well known to be consumed earlyon in oil aging. However, the dispersant stabilized borated controlledrelease friction modifier of the present invention is capable ofmaintaining a stable supply of friction modifier while the oil is aging.As both oils have equivalent viscosity and are in equivalent cars, the0.4 mpg improvement of composition 2B over comparative composition 2A iscaused by the low-ash dispersant stabilized borated controlled releasefriction modifier and its complex chemical interaction with thecomponents of the composition.

The invention being thus described, it will be obvious that the same maybe varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be obvious to one skilled in the art are to beincluded within the scope of the following claims.

What is claimed is:
 1. A lubricant composition, comprising: a controlledrelease friction modifier (CRFM); including: a tetrahedral borate anionhaving a boron atom with two bidentate di-oxo ligands both being alinear C₁₈-tartrimide; a first dispersant comprising a conventionalammonium substituted polyisobutenyl succinimide compound having apolyisobutenyl number average molecular weight of 750 to 2,500; a seconddispersant comprising an ammonium substituted polyisobutenyl succinimidecompound having an N:CO ratio of 1.8 and a polyisobutylenyl numberaverage molecular weight of 750 to 2,500; a highly paraffinic base stockselected from the group consisting of at least one Group III base stock,at least one Group IV polyalphaolefin (PAO) base stock and combinationsthereof; a third dispersant; and a detergent.
 2. The lubricantcomposition of claim 1, further comprising at least one of a Group Vco-base stock, an inorganic friction modifier, a viscosity modifier, anda cleanliness booster.
 3. The lubricant composition of claim 1, whereinthe third dispersant is selected from the group consisting ofsuccinimide, polyolefin amide alkeneamine, ethylene capped succinimide,borated polyisobutylsuccinimide-polyamine, and mixtures thereof.
 4. Thelubricant composition of claim 1, wherein the detergent is selected fromthe group consisting of highly overbased calcium salicylate, low basecalcium salicylate and overbased magnesium sulfonate, neutral calciumsulfonate and mixtures thereof.
 5. The lubricant composition of claim 3,wherein the Group V co-base stock is selected from the group consistingof esters, alkylated naphthalenes and mixtures thereof.
 6. The lubricantcomposition of claim 1, wherein the PAO base stock comprises up to 60 wt% of the composition.
 7. The lubricant composition of claim 1, whereinthe Group III base stock comprises 10-90 wt % of the composition.
 8. Thelubricant composition of claim 1, wherein the third dispersant comprises1-12 wt % of the composition.
 9. The lubricant composition of claim 1,wherein the detergent comprises 1-8 wt % of the composition.
 10. Thelubricant composition of claim 1, wherein the CRFM comprises 2-8 wt % ofthe composition.
 11. A lubricant composition, comprising: a controlledrelease friction modifier (CRFM) including: a tetrahedral borate anionhaving a boron atom with two bidentate di-oxo ligands both being alinear C₁₈-tartrimide; a first dispersant comprising a conventionalammonium substituted polyisobutenyl succinimide compound having apolyisobutenyl number average molecular weight of 750 to 2,500; a seconddispersant comprising an ammonium substituted polyisobutenyl succinimidecompound having an N:CO ratio of 1.8 and a polyisobutylenyl numberaverage molecular weight of 750 to 2,500; a highly paraffinic base stockselected from the group consisting of at least one Group III base stock,at least one Group IV polyalphaolefin (PAO) base stock or combinationsthereof; a third dispersant selected from the group consisting ofsuccinimide, polyolefin amide alkeneamine, ethylene capped succinimide,borated polyisobutylsuccinimide-polyamine and mixtures thereof; and adetergent selected from the group consisting of highly overbased calciumsalicylate, low base calcium salicylate and overbased magnesiumsulfonate, neutral calcium sulfonate and mixtures thereof.
 12. Thelubricant composition of claim 11, further comprising at least one of aGroup V co-base stock, an inorganic friction modifier, a viscositymodifier, and a cleanliness booster.
 13. The lubricant composition ofclaim 12, wherein the Group V co-base stock is selected from the groupconsisting of esters, alkylated naphthalenes and mixtures thereof. 14.The lubricant composition of claim 11, wherein the PAO base stockcomprises up to 60 wt % of the composition.
 15. The lubricantcomposition of claim 11, wherein the Group III base stock comprises10-90 wt % of the composition.
 16. The lubricant composition of claim11, wherein the third dispersant comprises 1-12 wt % of the composition.17. The lubricant composition of claim 11, wherein the detergentcomprises 1-8 wt % of the composition.
 18. The lubricant composition ofclaim 11, wherein the CRFM comprises 2-8 wt % of the composition.
 19. Alubricant composition, comprising: a controlled release frictionmodifier (CRFM) comprising 3.96 wt % of the composition, the CRFMincluding: a tetrahedral borate anion having a boron atom with twobidentate di-oxo ligands both being a linear C₁₈-tartrimide; a firstdispersant comprising a conventional ammonium substituted polyisobutenylsuccinimide compound having a polyisobutenyl number average molecularweight of 750 to 2,500; a second dispersant comprising an ammoniumsubstituted polyisobutenyl succinimide compound having an N:CO ratio of1.8 and a polyisobutylenyl number average molecular weight of 750 to2,500; a highly paraffinic base stock comprising at least one Group IIIbase stock, at least one Group IV polyalphaolefin (PAO) base stock,wherein the PAO base stock comprises 10-31.92 wt % of the compositionand the Group III base stock comprises 40-64.21 wt % of the composition;a third dispersant, wherein the dispersant comprises 4.44-5.4 wt % ofthe composition; and a detergent, wherein the detergent comprises2.03-3.83 wt % of the composition.